package com.yy.poly_.exercise_;

/**
 * chapter08  com.yy.poly_.exercise_
 * 2023-04-07 15:19
 *
 * @author yy yuyue
 * description : 不可描述
 * @date 2023/4/7 15:19
 */
public class PolyExerceise01 {
    public static void main(String[] args) {
        double d = 13.4;//ok
        long l = (long)d; //ok
        System.out.println(l);//13
        int in = 5;//ok
       // boolean b = (boolean)in; //不对 , boolean -> int
        Object obj = "Hello"; //可以,向上转型
        String objStr = (String)obj; //可以, 向下转型

        System.out.println(objStr); //hello
    }
}
